Luke 22:29

And I appoint unto you a kingdom, as my Father hath appointed unto me;

The appointment was made at the last Passover meal on the last evening with the disciples in the last hours before Christ offered Himself as a sacrifice for the world, after they yielded to strife and selfishly disputed over which of them should be counted greatest, in a wrong frame of mind that kept them from great blessing. Because they had continued with Him in His temptations, He appointed to them a kingdom just as the Father had appointed one to Him, where they would share His table in His kingdom by eating and drinking there and sit on thrones judging the twelve tribes of Israel.

Greatness in that kingdom is not Gentile lordship and exercise of authority, but becoming as the younger and the chief as one who serves, as He Himself was among them as one who serves, so that the greatest are those most humble and most active in serving their brethren. The kingdom promised is spiritual, and its honor means near and close communion with Christ and service under His direction and authority rather than worldly status, with eating and drinking at His table meaning admission to close communion with Him and with His servants administering the affairs of His kingdom under His direction.

The promise belongs to lowly, self-denying disciples who give others the preference, embodying compassion, love, self-denial and self-sacrifice rather than outward display, self-exaltation or seeking honor, and Christ values that character and true heart merit above outward display and gives distinction to those who embody it, with the self-sacrificing sitting nearest to Christ on His throne in positions of distinction. The promise will be fulfilled in the regeneration, when Christ returns in glory and sits on His throne to judge; the kingdom is not established on earth before then, but at the final judgment when the righteous receive their reward and the wicked are punished.

Christ has divine authority to bestow this kingdom because He possesses all that belongs to the Father and is one with the Father, sharing all the Father has, ruling from the eternal throne, receiving the honor due to God and the glory He had before the world existed, and He gives gifts to all who claim them by faith. The verse is encouragement to the faithful who do not seek honor but are counted worthy because of true heart merit. The promise warns those full of assurance and self-confidence, like Peter who presumptuously claimed readiness for prison and death and then fell, to learn strong persevering faith and entire trust in their Leader, finding strength not in what poor finite beings suppose they can do but in what Christ will do for them.